This should be a fairly easy job for some of the best out there. Reason why I say fairly as the packets are unencrypted and with packets you can do things like drop gold equip unequip move around and a ton of other things without being disconnected.
However with that being said. There is a problem. All packets are time stamped. So that I heard makes things a little harder then normal. In 10 years no one has been able to hack this game yet I honestly think it is because no one has tried.
I am no game hacker but some thoughts I have came up with are. Somehow stopping the damage packets in which you take from ever reaching the server. Or somehow modifying the packets to include extra experience.
Another thing I have thought about is while it may not be the above it would be better then nothing and that would be to somehow increase your damage to an outrageous number. I have heard of some people in game doing this yet it is not widely talked about as it would get fixed. You can not do it by normal means like using cheat engine or anything like that as it does not work. You can make it look like your damage is 1000k on your screen but the server still reads the correct data. I would even settle for this in lue of the above.